It's early 1942 in the western Pacific, and the Allies are reeling from the relentless onslaught of the Japanese Empire. Defeat follows defeat until the only vestige of Allied seapower left is a group of diesel-electric submarines based in The Philippines. They, too, are driven out, and seek safe harbor in Australia, in both Perth/Fremantle and Brisbane. While the rest of the Pacific Fleet is still recovering from Pearl Harbor, these boats go on the offensive and begin to sink Japanese ships. But not very many - years of peacetime have taken their toll on the boats' commanders, who seem to put keeping their subs safe well above damaging the enemy. They only attack submerged and rarely operate on the surface, which is where their radars can best find targets.

Then a new skipper shows up. He's younger than the others and a bit of a hardcase. He grew up in the coal fields of Kentucky and is no stranger to fighting. He tells the crew that their mission is to kill Japanese ships, and that he intends to do just that. He takes chances and scores sinking, many more than his brother skippers. His crew loves the fact that they're on a high-scoring boat but their captain is beginning to frighten them. His very conservative bosses are equally disturbed by some of his tactics, but when they try to rein him in, the big bosses back in Pearl intervene. Turn him loose, they tell the commanders in Australia. They don't call him the Iceman for nothing.